2015-09-27 16:05:31: ERROR[main]: UNRECOVERABLE error occurred. Stopping server. Please fix the following error:
2015-09-27 16:05:31: ERROR[main]: Lua: Node name is not set or is not a string!

In thread 7f44a9764740:
/home/telesight/minetest/src/server.cpp:511: void Server::step(float): A fatal error occurred: Lua: Node name is not set or is not a string!
Debug stacks:
DEBUG STACK FOR THREAD 7f4493fff700:
#0  virtual void* EmergeThread::Thread()
(Leftover data: #1  MapBlock* ServerMap::loadBlock(v3s16))
(Leftover data: #2  void ServerMap::loadBlock(std::string*, v3s16, MapSector*, bool))
(Leftover data: #3  void ItemStack::deSerialize(std::istream&, IItemDefManager*))
DEBUG STACK FOR THREAD 7f44a11df700:
#0  virtual void* ServerThread::Thread()
#1  void Server::Receive()
(Leftover data: #2  void Server::SendBlocks(float))
(Leftover data: #3  void RemoteClient::GetNextBlocks(ServerEnvironment*, EmergeManager*, float, std::vector<PrioritySortedBlockTransfer>&))
(Leftover data: #4  MapBlock* ServerMap::loadBlock(v3s16))
(Leftover data: #5  void ServerMap::loadBlock(std::string*, v3s16, MapSector*, bool))
(Leftover data: #6  void ItemStack::deSerialize(std::istream&, IItemDefManager*))
DEBUG STACK FOR THREAD 7f44a9764740:
#0  int main(int, char**)
#1  Dedicated server branch
#2  void dedicated_server_loop(Server&, bool&)
#3  void Server::step(float)